The interdisciplinary COST Action ‘Colour and Space in Cultural Heritage' brings together some 120 researchers from 26 countries. We represent a wide range of backgrounds, specialisms and discrete research interests. We also have much in common. We appreciate the beauty of art and the significance of cultural heritage. We believe in the best possible documentation of artefacts as an essential means of their conservation and preservation, for their study and education. The accurate measurement of colour and shape is a critical, yet by no means trivial, part of 3D documentation. In COSCH, specialists in optical and imaging technologies collaborate with a community of users representing a wide range of application areas. We are determined to reach a common understanding of current needs and possibilities. We work towards a conceptual, scientific, technical and procedural consensus in defining best standards in heritage documentation.

The Authors of six papers included in this issue introduce a range of scientific questions pertinent to spatial and spectral documentation of material objects. They include the question of the fusion of technical standards in the measurement of colour and shape; the fusion of standards and the integration of techniques and instruments that are typically applied independently; and the automation of some digitisation processes. Although the focus is on optical science, collectively the Authors contribute to a much broader discussion of heritage science and its significance for modern documentation of material culture. All papers but one discuss applications of technology to art and/or archaeological material. A presentation of a low-cost, contact-less optical technology, combining stereovision with the projection of structured-light patterns, for measuring in 3D the shape of objects alongside their RGB colour texture, resorts to the use of a mannequin. Other papers report on applications of technology to recording actual works of art and archaeological sites, ranging from the spectacular paintings in the cave of Altamira and other Palaeolithic cave art of Northern Spain, inscribed into the UNESCO World Heritage List, the Late Antique/Early Byzantine workshop and milling complex in Terrace House 2 in Ephesos, Turkey (a concise overview of the history of excavations at Ephesos with photographs can be found on the Austrian Archaeological Institute website through to Pablo Picasso's early painting from the Blue Period, portraying the Woman in Blue, now in the Museo Reina Sofia in Madrid. When exhibited in 1901 the portrait went unnoticed by contemporary critics. Disappointed Picasso left it uncollected. The painting was rediscovered in the 1950s, discoloured and in need of treatment (read more). One of the papers reports on spectral reflectance measurements supporting monitoring of how the paint behaves over the time and evaluating the perceived effect of the restoration. The scientific papers included in this issue were originally presented at the COSCH session of the Denkmäler 3D Conference, held in Dortmund on 18 October 2013. The papers have been peer-reviewed and appear here in revised and considerably extended versions.

The Authors' discussion is concerned with heritage science; artistic and historical insights are limited. The scope of papers did not allow for coverage of non-technical information pertinent to the significance of these works. However, documentation of cultural heritage can only be effective if comprehensive. The aggregation of all information and knowledge that is essential for research, conservation, education and popular appreciation of cultural heritage constitutes an interdisciplinary challenge. We will report in due course how COSCH is addressing this particular issue.

The COSCH community is made up of eminent specialists and aspiring young researchers. Short biographies of contributors to this issue are included in the COSCH Who's-Who?. Such biographical statements typically start with details of doctoral research. The formation of one's career goes back to much earlier years and often involves events whose significance is appreciated through the benefit of hindsight. Some internationally renowned architects, for example, credit their fascination with construction of space to toys with which they played as boys. The wooden Froebel bricks are known to have been favourites with Frank Lloyd Wright and Le Corbusier. The co-designer of the Centre Pompidou in Paris, Richard Rogers, played with Meccano. Lego impacted on the future career of Bjarke Ingels, whose Danish company BIG still uses the medium in daily practice. On this lighter note, you are invited to find out what the COSCH Chairman liked to play with as a child!